VirtualBox v4.3 Beta 2 is released. VirtualBox is a general-purpose full virtualizer for x86/x64 hardware. Targeted at server, desktop and embedded use, it is now the only professional-quality virtualization solution that is also Open Source Software.

VirtualBox v4.3 Beta 2 Changelog:
VMM: fixed several regressions; fixed accessing certain MSRs (Intel and AMD)
VMM: fixed 64-bit guests on 32-bit hosts including fixes for host crashes under certain conditions (see 11979).
VMM: fixed panics on Mac OS X, see here
VMM: allow to use VT-x in SMX mode
GUI: more settings validation fixes
GUI: medium enumeration overhaul to speed up opening the settings dialog
GUI: fixed crashes under certain conditions on X11 hosts
Main: extension pack framework can now support loading HGCM modules, contributed by Jeff Westphal
Settings: the exclusive HW virtualization setting is now global, not per-VM as before
NAT: fixed port-forwarding
NAT: binding IPv4 connectivity to specified interface (global extradata "NAT//SourceIp4" ipv4)
NAT: DHCP reports list of DNS servers (w/o loopback mapping)
USB: detect USB2 devices on USB3 ports (Windows hosts only)
OVF: fixed import regression with double OHCI controller
3D: fixed 3D-related crashes and Windows 8.1 rendering issues on OSX hosts
3D: fixed Ubuntu 13.04 3D desktop rendering issues
Solaris hosts: dropped 32-bit support
Windows Additions: several autoresize and seamless fixes
Windows Additions: updated Wine sources
Windows Additions: fixed NT4 regression, see here

Download: VirtualBox v4.3 Beta 2
Source: Here